
Mike and Sully work to treat a typhus epidemic at Black Kettle's camp, which begins after Mike and Sully unwittingly convince Black Kettle to accept government blankets infected with the virus. Mike is heartbroken and guilt-ridden as she battles the tribe's typhus epidemic. When Matthew comes down with typhus, the town panics and locks the children in the clinic alone with Horace. Colleen treats Matthew and Horace contrives to send the kids out to the reservation to be with Mike. Meanwhile, the town prepares for the Fourth of July, ironically missing the point entirely that the first Americans, the Indians, are being systematically wiped out and further, that the newest Americans, the Immigrants, have just had their camp destroyed by the typhus-fearing townsfolk
After Snowbird gives Mike an Indian pony, Flash, in thanks for her work at the reservation Mike tries to enter the Territory Stakes Race, but race officials, Loren and Jake, won't allow a woman to ride. Dr. Cassidy arrives from Denver with his champion horse and spurns Mike attempts to speak to him colleague to colleague. Dr. Cassidy's rider, Drew, is injured and Mike diagnoses cranial compression, yet Dr. Cassidy refuses Mike's assistance. Drew dies and an angry Mike is determined to enter the race, disguised as a man. Meanwhile, with encouragement from Grace, Brian enters a pie-baking contest and is met with skepticism from Colleen and Loren. To everyone's surprise, Brian is declared the winner. Mike rides the race of her life and wins, but is disqualified when her disguise is revealed and Hank, riding Dr. Cassidy's horse, is declared the winner.